Someone completely devoid of any semblance of math skills. Likely going to major in some liberal arts/language program and earn a paltry salary, regretting their childhood.
Kristi was quite the mathtard in classtoday. She thought pi was somewhere between 2 and 3.
The complete inability to perform basic mathematical functions. This can be caused by a long lapse in time between math classes causing brain atrophy, or general retardedness.
I am completely mathtarded in my college algebra class, probably because i haven't taken a math class in three years.